Example3 Heat Radiation of IC by Forced Convection

General

Heat dissipation of an IC on the substrate by the forced convection is solved by the steady-state analysis.
The temperature distribution and the heat flux vectors are solved.
Unless specified in the list below, the default conditions will be applied.
Obtain this session's project file. (Save the project file before open)

Analysis Space

Item	Setting
Analysis Space	3D
Model Unit	mm

Show Results

Item	Setting
Solver	Fluid Analysis [Bernoulli] Thermal analysis [Watt]
Analysis Type	Steady-State Analysis
Laminar Flow/Turbulent Flow	Select Turbulent Flow
Meshing Setup	General Mesh size: 5 [mm]

Model

The model is a box solid body. The material is Air (000_Air). The boundary conditions of inlet and outlet are set on the left edge and the right edge respectively.

The slip wall outer boundary condition is applied to the top and bottom edges where the boundary condition is not set.

The substrate (VOL1) and IC (VOL2) are solid bodies.

Setting of Body Attributes, Materials, and Mesh Sizes

Body Number/Type	Body Attribute Name	Material Name	Mesh Size
0/Solid	VOL1	006_Glass_epoxy *	0.2
1/Solid	VOL2	001_Alumina *	0.2
2/Solid	Air	000_Air(*)	–

* Available from the material DB

IC (VOL2) is set as follows on the Heat source tab.

Body Attribute Name	Tab	Setting
VOL2	Heat Source	1W

Boundary Condition

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Setting
In/Edge	Thermal Fluid	Inlet	Forced Inflow Specify fluid velocity 1[m/s] Inflow Temperature : 25[deg]
Out/Face	Thermal Fluid	Outlet	Natural Outflow
Outer Boundary Condition	Thermal Fluid	Slip wall	–

Results

The temperature distribution is shown below.

For easy viewing of the temperature distributions of the substrate and the IC, the ambient air field is hidden by right-clicking the air body and selecting [Hide Body Field].

As the upstream side is more likely to get cooler, the temperature distribution is biased. The temperature on the downstream side of the substrate surface is higher than the upstream side.